Someone got so angry over another person’s bad parking job, they took the time to write them a long, seemingly heartfelt letter with a dark twist at the end intended to teach the driver a very nasty lesson.

The note — posted Tuesday on Twitter, Reddit and Imgur — starts off with an anecdote about the writer’s grandfather quitting smoking.

“To whoever owns this car…My grandfather smoked his whole life. I was about 10 years old when my mother said to him, ‘If you ever want to see your grandchildren graduate, you need to stop immediately,”” the letter reads. “Tears welled up in his eyes when he realized exactly what was at stake. He quit cold-turkey that very day. Three years later [my grandfather] died of lung cancer.

“We were very close, and his death destroyed me,” the writer adds. “My mother said to me, ‘Please never smoke, don’t put your family through what your grandfather put us through.’ I agreed. At 18, I have never touched a cigarette.”

Just when the story seems to take a heartwarming turn, the man delivers his gut-wrenching punchline.

“I must say, I feel a very slight sense of regret for never having done it,” he says. “For never having done it because your parking job was so s**tty it gave me cancer anyway. Jesus f**k, please learn how to park.”

The letter has been viewed more than 180,000 times on Imgur and liked over 170,000 times on Twitter, where it was posted Tuesday by a young woman named Sarah Bryant.

“I just found this on someone’s car,” she claimed. “I have no words.”

Bryant told users that the letter had her completely fooled at first.

“I seriously started tearing up and then finished reading & was like…alrighty then,” she said, insisting she wasn’t the driver who parked bad.